[CLOSED-591] scrolled text jumps back

Sencha Touch version tested:

1.0 rev ____

only default sench-touch.css

Platform tested against:

iOS 4

Description:

Created a panel with text that goes offscreen.
Panel is set to scroll vertically.
Text scrolls with touch/drag, but when released goes back to original position.
This makes it impossible to reach the bottom of the text.